Energy Flow through Ecosystems.

Authors Avatar

Emily 12JS              Energy Flow through Ecosystems                25/01/02

Introduction

Energy cannot be recycled, created or destroyed; it can only be transferred from one form to another. In most ecosystems, the original source of energy is the sun. Energy is lost from an ecosystem when it is used up or when lost as heat. It flows through an ecosystem in a food chain. Only 10% of energy present in a particular trophic level can be found in the successive trophic level of that food chain. This means that in order to provide enough energy to consumers, the number of organisms that can be supported goes down ascending trophic levels.

Primary producers

Primary production is the ‘synthesis and storage of organic molecules during growth and reproduction of photosynthetic organisms.’ Primary producers are called autotrophs because they manufacture their own nutrition. The most commonly known producers are plants. The plants use red and blue wavelengths from sunlight to carry out the process of photosynthesis i.e. the conversion of carbon dioxide and water into carbohydrates and oxygen. The carbohydrates they produce provide energy for heterotorophs ie. consumers.

However only a small percentage of the sunlight that reaches the plant ends up as NPP ( Net Primary Production- the totoal energy fixed as biomass and available for heterotrophs.) Energy is lost even in the first trophic level of a food chain when portions of the energy available to the leaf is:

Join now!

  1. Reflected by the leaf
  2. Of the wrong wavelength to be absorbed by chlorophyll
  3. Transmitted straight through the leaf
  4. Consumed due to the process of photosynthesis
  5. Lost by respiration

Primary Consumers:

Primary consumers are heterotropic; they obtain their nutrition by consuming other organisms. They obtain their energy by eating producers e.g. plants, however only a small proportion of the energy intake from feeding will be available as energy to a secondary consumer. Energy is lost from the system in:

  1. The process of respiration
  2. Urine
  3. Faeces
  4. Heat
  5. The production of biomass i.e. the energy ...

This is a preview of the whole essay